The buyers, also including Stone Point Capital LLC and
Geneva-based Edmond de Rothschild Group, will pay $15.55 a
share, 19 percent more than Duff & Phelps’s closing price on
Dec. 28. The transaction is expected to be completed in the
first half, the companies said in a statement yesterday.

The group of buyers will help New York-based Duff & Phelps
continue its international expansion, according to the
statement. Revenue at the 80-year-old firm, which also provides
financial-advisory services, is predicted to rise 17 percent
this year to $465.8 million, the average of analysts’ estimates
compiled by Bloomberg.

Shares of Duff & Phelps, which has more than 1,000
employees worldwide, have declined 10 percent this year, while
the Standard & Poor’s 500 Index gained 12 percent. The stock
advanced 1.9 percent to $13.05 on Dec. 28, below the 2007
initial public offering price of $16.

Private-equity firm Carlyle, based in Washington, has
jumped 18 percent since its May IPO. This month, the firm agreed
to buy a stake in energy investor NGP Energy Capital Management
for $424 million. Other deals this year included the photo
archive Getty Images Inc. and DuPont Co.’s auto-paint unit.

‘Go-Shop Period’

The Duff & Phelps merger agreement provides for a “go-
shop” period ending on Feb. 8, during which the company can
solicit and receive alternative proposals. Duff & Phelps would
pay a break-up fee of about $6.65 million if it gets a higher
bid and ends the agreement before March 8.

Duff & Phelps, started in 1932 to provide investment
research, was a financial adviser to the examiner in the Lehman
Brothers Holdings Inc. bankruptcy in 2009 and an administrator
for the Rangers Football Club Plc in the largest soccer club
insolvency in U.K. history, according to its website.